Self-cleaning litter box

Abstract

A self-cleaning litter box for cats employs a comb drive to drive a comb through litter to remove waste from the litter. A sensor for detecting the presence of an obstruction is coupled to the comb drive and stops the comb drive upon detecting an obstruction. A manual mode selector switch and an actuating switch are provided to manually activate the cleaning of the litter box at a time deemed appropriate by the cat owner. A foot pedal unit may be provided for semi-automatic use. A removable tray for cat litter may be provided. The tray may be disposable. A pivotable ramp facilitates ingress to, and egress from, the litter box. The ramp may be carpeted. A tray receives the litter box and a hood encloses the litter box to provide privacy.

What is claimed as new and desired to be protected by Letters Patent of the United States is: 
     
       1. A litter box, comprising a housing for receiving litter;   a comb disposed in said housing;   a motor for moving the comb from the first position to a second position; and   a sensor for sensing contact by the comb with an obstruction as the comb is moved from the first position to the second position.   
     
     
       2. The litter box of claim 1, wherein said sensor provides a shut-off signal when said sensor detects contact with a cat. 
     
     
       3. The litter box of claim 2, wherein said sensor includes a switch coupled to said motor, said switch being movable between an open position and a closed position, the sensor providing the shut-off signal when the switch is in the closed position. 
     
     
       4. The litter box of claim 1, wherein said sensor includes a leaf switch. 
     
     
       5. The litter box of claim 1, further comprising: a mode selector switch movable between a manual operation selecting position and an automatic operation selecting position; and   a manual operation switch electrically connected to said mode selector switch for driving said comb from said first position to said second position in response to actuation of said manual operation switch when said mode selector switch is in the manual operation selecting position.   
     
     
       6. The litter box of claim 5, wherein said manual operation switch includes a foot pedal. 
     
     
       7. The litter box of claim 1, further comprising a removable litter tray. 
     
     
       8. The litter box of claim 1, further comprising a replaceable waste receptacle. 
     
     
       9. The litter box of claim 8, wherein said waste receptacle has a lid, and wherein said litter box further includes means for lifting said lid in response to movement of said comb. 
     
     
       10. A self-cleaning cat litter box, comprising: a housing defining a litter chamber for receiving cat litter;   a comb disposed in said litter chamber;   a comb drive coupled to said housing, said comb drive including a drive motor; and   a sensor coupled to the drive motor and positioned to detect contact with an obstruction, wherein the sensor generates a signal to change the state of said comb in response to said contact.   
     
     
       11. The cat litter box of claim 10, further comprising parallel side walls for preventing debris from spilling out of the cat litter box. 
     
     
       12. The cat litter box of claim 10, wherein said housing is provided with rounded corners to facilitate cleaning, and wherein said litter chamber has no small spaces of the type which would permit litter or waste to slip out of or become lodged in said box. 
     
     
       13. A self-cleaning cat litter box, comprising: a housing defining a litter chamber;   a comb disposed in said housing;   a comb drive coupled to said housing;   a mode selector switch movable between a manual operation selecting position and an automatic operation selecting position, said comb drive driving said comb in response to a signal from a controller when said mode selector switch is in the automatic operation selecting position; and   a manual operation switch electrically connected to said mode selector switch, said comb drive driving said comb in response to actuation of said manual operation switch when said mode selector switch is in the manual operation selecting position.   
     
     
       14. The self-cleaning cat litter box of claim 13, further comprising a housing access ramp pivotally connected to said housing. 
     
     
       15. The self-cleaning cat litter box of claim 13, further comprising a tray having side walls and a bottom wall that cooperate to define a housing-receiving region, a plurality of hood supports coupled to said tray, and a hood coupled to said supports, said hood having an opening. 
     
     
       16. The self-cleaning cat litter box of claim 13, further comprising a removable litter tray for receiving cat litter. 
     
     
       17. A method of cleaning waste from a cat litter box, comprising the steps of: operating said litter box according to a manual cleaning mode;   subsequently, switching said litter box to an automatic mode configuration;   subsequently, operating said litter box according to an automatic mode; and   detecting an obstruction.   
     
     
       18. The method of claim 17, further comprising the step of stopping the movement of a comb in response to detection of the obstruction. 
     
     
       19. The method of claim 18, further comprising the step of reversing the direction of movement of the comb in response to detection of said obstruction. 
     
     
       20. The method of claim 17, further comprising the step of disabling operation of said litter box for a predetermined period of time. 
     
     
       21. The method of claim 20, further comprising the step of actuating an over-ride system to operate said litter box during said predetermined period of time.